See evidence of “gravitational wasting” erosion on Bay Area hillsides.
Vetch and Argentine ants cooperate, exchanging food for protection.
A quiet winter woodland can suddenly explode with bird life. Jack Laws explains how to tell some of the common species apart.
Native to China, Craspedacusta sowerbii is found in freshwater lakes and ponds on every continent.
Ant lions trap their prey in steep pits.
Watching distant raptors in dim light? Ignore color and look at values.
Life is so surprisingly webbed and interconnected.
Every fall thousands of Vaux’s swifts migrate south, congregating at dusk in swirling flocks. Here’s how to find them when they pass through the Bay Area.